Dtk::Core::DFileSystemWatcher类 参考

The DFileSystemWatcher class provides an interface for monitoring files and directories for modifications. 更多...

类 Dtk::Core::DFileSystemWatcher 继承关系图:

信号
void	fileDeleted (const QString &path, const QString &name, QPrivateSignal)
void	fileAttributeChanged (const QString &path, const QString &name, QPrivateSignal)
void	fileClosed (const QString &path, const QString &name, QPrivateSignal)
void	fileMoved (const QString &fromPath, const QString &fromName, const QString &toPath, const QString &toName, QPrivateSignal)
void	fileCreated (const QString &path, const QString &name, QPrivateSignal)
void	fileModified (const QString &path, const QString &name, QPrivateSignal)

Public 成员函数
	DFileSystemWatcher (QObject *parent=Q_NULLPTR)
	DFileSystemWatcher (const QStringList &paths, QObject *parent=Q_NULLPTR)
	~DFileSystemWatcher ()
bool	addPath (const QString &file)
QStringList	addPaths (const QStringList &files)
bool	removePath (const QString &file)
QStringList	removePaths (const QStringList &files)
QStringList	files () const
QStringList	directories () const

额外继承的成员函数
Protected 成员函数 继承自 Dtk::Core::DObject
	DObject (DObject *parent=nullptr)
	只有在不需要数据成员的派生类中才会使用 parent 父类指针
	DObject (DObjectPrivate &dd, DObject *parent=nullptr)
	在派生类中比较常用的构造函数 dd 私有类对象
Protected 属性 继承自 Dtk::Core::DObject
QScopedPointer< DObjectPrivate >	d_d_ptr

详细描述

The DFileSystemWatcher class provides an interface for monitoring files and directories for modifications.

\inmodule dtkcore

DFileSystemWatcher monitors the file system for changes to files and directories by watching a list of specified paths.

Call addPath() to watch a particular file or directory. Multiple paths can be added using the addPaths() function. Existing paths can be removed by using the removePath() and removePaths() functions.

DFileSystemWatcher examines each path added to it. Files that have been added to the DFileSystemWatcher can be accessed using the files() function, and directories using the directories() function.

The fileChanged() signal is emitted when a file has been modified, renamed or removed from disk. Similarly, the directoryChanged() signal is emitted when a directory or its contents is modified or removed. Note that DFileSystemWatcher stops monitoring files once they have been renamed or removed from disk, and directories once they have been removed from disk.

注解

On systems running a Linux kernel without inotify support, file systems that contain watched paths cannot be unmounted.

Windows CE does not support directory monitoring by default as this depends on the file system driver installed.

The act of monitoring files and directories for modifications consumes system resources. This implies there is a limit to the number of files and directories your process can monitor simultaneously. On all BSD variants, for example, an open file descriptor is required for each monitored file. Some system limits the number of open file descriptors to 256 by default. This means that addPath() and addPaths() will fail if your process tries to add more than 256 files or directories to the file system monitor. Also note that your process may have other file descriptors open in addition to the ones for files being monitored, and these other open descriptors also count in the total. OS X uses a different backend and does not suffer from this issue.

\inmodule dtkcore

DFileSystemWatcher monitors the file system for changes to files and directories by watching a list of specified paths.

Call addPath() to watch a particular file or directory. Multiple paths can be added using the addPaths() function. Existing paths can be removed by using the removePath() and removePaths() functions.

DFileSystemWatcher examines each path added to it. Files that have been added to the DFileSystemWatcher can be accessed using the files() function, and directories using the directories() function.

注解

On systems running a Linux kernel without inotify support, file systems that contain watched paths cannot be unmounted.

Windows CE does not support directory monitoring by default as this depends on the file system driver installed.

The act of monitoring files and directories for modifications consumes system resources. This implies there is a limit to the number of files and directories your process can monitor simultaneously. On all BSD variants, for example, an open file descriptor is required for each monitored file. Some system limits the number of open file descriptors to 256 by default. This means that addPath() and addPaths() will fail if your process tries to add more than 256 files or directories to the file system monitor. Also note that your process may have other file descriptors open in addition to the ones for files being monitored, and these other open descriptors also count in the total. OS X uses a different backend and does not suffer from this issue.

\inmodule dtkcore

DFileSystemWatcher monitors the file system for changes to files and directories by watching a list of specified paths.

Call addPath() to watch a particular file or directory. Multiple paths can be added using the addPaths() function. Existing paths can be removed by using the removePath() and removePaths() functions.

DFileSystemWatcher examines each path added to it. Files that have been added to the DFileSystemWatcher can be accessed using the files() function, and directories using the directories() function.

The fileChanged() signal is emitted when a file has been modified, renamed or removed from disk. Similarly, the directoryChanged() signal is emitted when a directory or its contents is modified or removed. Note that DFileSystemWatcher stops monitoring files once they have been renamed or removed from disk, and directories once they have been removed from disk.

注解

On systems running a Linux kernel without inotify support, file systems that contain watched paths cannot be unmounted.

Windows CE does not support directory monitoring by default as this depends on the file system driver installed.

The act of monitoring files and directories for modifications consumes system resources. This implies there is a limit to the number of files and directories your process can monitor simultaneously. On all BSD variants, for example, an open file descriptor is required for each monitored file. Some system limits the number of open file descriptors to 256 by default. This means that addPath() and addPaths() will fail if your process tries to add more than 256 files or directories to the file system monitor. Also note that your process may have other file descriptors open in addition to the ones for files being monitored, and these other open descriptors also count in the total. OS X uses a different backend and does not suffer from this issue.

参见

QFile, QDir

构造及析构函数说明

DFileSystemWatcher() [1/2]

Dtk::Core::DFileSystemWatcher::DFileSystemWatcher

(

QObject *

parent = Q_NULLPTR

)

Constructs a new file system watcher object with the given parent.

DFileSystemWatcher() [2/2]

Dtk::Core::DFileSystemWatcher::DFileSystemWatcher	(	const QStringList &	paths,
		QObject *	parent = Q_NULLPTR
	)

Constructs a new file system watcher object with the given parent which monitors the specified paths list.

~DFileSystemWatcher()

Dtk::Core::DFileSystemWatcher::~DFileSystemWatcher

(

)

Destroys the file system watcher.

成员函数说明

addPath()

bool Dtk::Core::DFileSystemWatcher::addPath

(

const QString &

path

)

Adds path to the file system watcher if path exists. The path is not added if it does not exist, or if it is already being monitored by the file system watcher.

If path specifies a directory, the directoryChanged() signal will be emitted when path is modified or removed from disk; otherwise the fileChanged() signal is emitted when path is modified, renamed or removed.

If the watch was successful, true is returned.

Reasons for a watch failure are generally system-dependent, but may include the resource not existing, access failures, or the total watch count limit, if the platform has one.

注解

There may be a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit is been reached, path will not be monitored, and false is returned.

参见

addPaths(), removePath()

addPaths()

QStringList Dtk::Core::DFileSystemWatcher::addPaths

(

const QStringList &

paths

)

Adds each path in paths to the file system watcher. Paths are not added if they not exist, or if they are already being monitored by the file system watcher.

If a path specifies a directory, the directoryChanged() signal will be emitted when the path is modified or removed from disk; otherwise the fileChanged() signal is emitted when the path is modified, renamed, or removed.

The return value is a list of paths that could not be watched.

Reasons for a watch failure are generally system-dependent, but may include the resource not existing, access failures, or the total watch count limit, if the platform has one.

注解

There may be a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit has been reached, the excess paths will not be monitored, and they will be added to the returned QStringList.

参见

addPath(), removePaths()

directories()

QStringList Dtk::Core::DFileSystemWatcher::directories

(

)

const

Returns a list of paths to directories that are being watched.

参见

files()

files()

QStringList Dtk::Core::DFileSystemWatcher::files

(

)

const

Returns a list of paths to files that are being watched.

参见

directories()

removePath()

bool Dtk::Core::DFileSystemWatcher::removePath

(

const QString &

path

)

Removes the specified path from the file system watcher.

If the watch is successfully removed, true is returned.

Reasons for watch removal failing are generally system-dependent, but may be due to the path having already been deleted, for example.

参见

removePaths(), addPath()

removePaths()

QStringList Dtk::Core::DFileSystemWatcher::removePaths

(

const QStringList &

paths

)

Removes the specified paths from the file system watcher.

The return value is a list of paths which were not able to be unwatched successfully.

Reasons for watch removal failing are generally system-dependent, but may be due to the path having already been deleted, for example.

参见

removePath(), addPaths()

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该类的文档由以下文件生成:

• src/filesystem/dfilesystemwatcher.h
• src/filesystem/dfilesystemwatcher_dummy.cpp
• src/filesystem/dfilesystemwatcher_linux.cpp
• src/filesystem/dfilesystemwatcher_win.cpp